Cooling assembly and dehumidification method

ABSTRACT

A cooling assembly includes a device chamber containing a device chamber cooling medium, a heat exchanger including at least one cooling surface in contact with the device chamber cooling medium, a control unit configured to control the heat exchanger, a humidity sensor configured to detect a humidity level in the device chamber, and a receptacle. The control unit is configured to perform a dehumidification operation as a response to the humidity level exceeding a predetermined threshold value in the device chamber. The dehumidification operation includes lowering a temperature of the at least one cooling surface in order to condensate water from the device chamber cooling medium on the at least one cooling surface. The receptacle is configured to receive water dripping from the at least one cooling surface.

RELATED APPLICATION

This application claims priority under 35 U.S.C. §119 to European Patent Application No. 13153815.9 filed in Europe on Feb. 4, 2013, the entire content of which is hereby incorporated by reference in its entirety.

FIELD

The present disclosure relates to a cooling assembly and to a dehumidification method.

BACKGROUND INFORMATION

Humidity is harmful to many electronic components. Humidity is an issue, for example, in solar power plants and wind power plants. Challenging environments such as tropical or arctic climates increase problems caused by humidity.

In a known method, air inside a device chamber is heated after which the heated moist air is discharged from the device chamber, and the cycle is repeated until air inside the device chamber is warm and dry. It is also known to use water absorbing materials such as silica gel to remove humidity from a device chamber.

Dehumidification by repeated drying cycles discharging heated humid air and replacing the discharged air with colder ambient air is a relatively slow process requiring plenty of energy. Water absorbing materials are expensive and their useful life is limited.

SUMMARY

An exemplary embodiment of the present disclosure provides a cooling assembly which includes a device chamber containing a device chamber cooling medium, heat exchanger means comprising at least one cooling surface in contact with the device chamber cooling medium, control means for controlling the heat exchanger means, humidity sensor means for detecting a humidity level in the device chamber, and a receptacle. The control means is configured to perform a dehumidification operation as a response to the detected humidity level exceeding a predetermined threshold value in the device chamber. The dehumidification operation comprises lowering a temperature of the at least one cooling surface to condensate water from the device chamber cooling medium on the at least one cooling surface. The receptacle is configured to receive water dripping from the at least one cooling surface.

An exemplary embodiment of the present disclosure provides a dehumidification method which includes detecting a humidity level in a device chamber containing a device chamber cooling medium. As a response to the detected humidity level exceeding a predetermined threshold value in the device chamber, the exemplary method also includes lowering a temperature of at least one cooling surface in contact with the device chamber cooling medium to condensate water from the device chamber cooling medium on the at least one cooling surface. In addition, the exemplary method includes collecting water dripping from the at least one cooling surface in a receptacle.

BRIEF DESCRIPTION OF THE DRAWINGS

Additional refinements, advantages and features of the present disclosure are described in more detail below with reference to exemplary embodiments illustrated in the drawings, in which:

FIG. 1 shows a cooling chamber according to an exemplary embodiment of the present disclosure.

DETAILED DESCRIPTION

Exemplary embodiments of the present disclosure provide a method and an apparatus for implementing the method so as to alleviate the above disadvantages. Exemplary embodiments of the present disclosure provide a dehumidification method and a cooling assembly as described herein.

Exemplary embodiments of the present disclosure are based on the idea of condensing water from a device chamber cooling medium by cooling thereof at a safe place at a distance from electronic components that could be damaged by humidity. The condensed water may be discharged from a device chamber containing the electronic components or stored inside the device chamber in a harmless place where the water does not endanger the electronic components.

An advantage of the method and assembly of the present disclosure is that the cooling medium in a device chamber can be dried relatively fast without need to discharge heated cooling medium from the device chamber.

In the following, exemplary embodiments of the present disclosure will be described in greater detail with reference to FIG. 1 illustrating a cooling assembly according to an exemplary embodiment of the disclosure.

FIG. 1 shows a cooling assembly including a device chamber 2, a cooling chamber 4, heat exchanger means, humidity sensor means 61 (e.g., a humidity sensor), heating means 26 (e.g., a heater), device chamber fan means 51 (e.g., a fan in the device chamber 2), cooling chamber fan means 52 (e.g., a fan in the cooling chamber 4), control means 6 (e.g., a computer processor configured to execute a computer program and/or computer-readable instructions tangibly recorded on a non-transitory computer-readable recording medium, such as a non-volatile memory), a receptacle 9, and a discharge tube 92. The device chamber 2 contains, for example, air as a device chamber cooling medium, and the cooling chamber 4 contains, for example, air as a cooling chamber cooling medium. The device chamber 2 is separated from the cooling chamber 4 such that there is substantially no cooling medium flow between the device chamber 2 and the cooling chamber 4.

The heat exchanger means include a device chamber cooling unit 3 and an internal heat exchanger unit 10. The device chamber cooling unit 3 is configured for transferring heat from the device chamber 2 to the cooling chamber 4. The device chamber cooling unit 3 includes a first portion 31 located in the device chamber 2 and a second portion 32 located in the cooling chamber 4. The first portion 31 is in an operating situation located lower than the second portion 32. The first portion 31 has a cooling surface 35 in contact with the device chamber cooling medium. The internal heat exchanger unit 10 is configured for transferring heat from a cooling surface 15 of the internal heat exchanger unit 10 to a hot surface 16 of the internal heat exchanger unit 10. Both the cooling surface 15 of the internal heat exchanger unit 10 and the hot surface 16 of the internal heat exchanger unit 10 are in contact with the device chamber cooling medium. The hot surface 16 is cooled by circulation of the device chamber cooling medium.

A cooling assembly according to another exemplary embodiment of the present disclosure does not include a cooling chamber. A device chamber cooling unit of such an embodiment is configured to transfer heat out of the device chamber, for example, to ambient air surrounding the device chamber.

According to an exemplary embodiment, the device chamber cooling unit 3 is a cothex type heat exchanger. A cothex is a thermosyphon heat exchanger where a cooling medium circulates by means of natural convection without a mechanical pump. In an alternative embodiment, a heat exchanger configured to transfer heat out of the device chamber may include another type of passive heat exchanger, or an active heat exchanger.

According to an exemplary embodiment, the internal heat exchanger unit 10 is a Peltier cooler or a thermoelectric cooler configured to use a Peltier effect to transfer heat from the cooling surface 15 to the hot surface 16. In an alternative embodiment, an internal heat exchanger unit configured to transfer heat from a cooling surface of the internal heat exchanger unit to elsewhere inside the device chamber may include a heat exchanger whose type is other than a thermoelectric cooler.

The cooling chamber fan means 52 are configured for regulating a cooling chamber cooling medium flow interacting with the second portion 32 of the device chamber cooling unit 3. The cooling chamber fan means 52 are capable of exhausting warm air from the cooling chamber and drawing in cold air from the exterior of the cooling assembly. Increasing the cooling chamber cooling medium flow increases a cooling power of the device chamber cooling unit 3. The control means 6 are configured to control the cooling chamber fan means 52.

The humidity sensor means 61 are configured to detect a humidity level in the device chamber 2, and to provide the control means 6 with information relating to the detected humidity level. The control means 6 are configured to control the heat exchanger means, and to perform a dehumidification operation as a response to the humidity level exceeding a predetermined threshold value in the device chamber 2. In accordance with an exemplary embodiment, the duration of a dehumidification operation is constant, the duration being rated for the cooling assembly in question. Duration of the dehumidification operation may be from 1 to 3 minutes, for example. In accordance with another exemplary embodiment, the control means 6 are configured to continue a dehumidification operation until device chamber cooling medium is sufficiently dry.

In accordance with exemplary embodiments of the present disclosure, a decisive humidity level value is a relative humidity level. Since relative humidity level is a function of temperature, the cooling assembly of FIG. 1 is depicted with a separate temperature sensor 62 configured to detect a temperature in the device chamber 2. Alternatively, an integrated relative humidity sensor may be used. Since relative humidity of air further depends on pressure, a cooling assembly may be equipped with a pressure sensor.

The dehumidification operation includes lowering a temperature of the cooling surface 35 of the device chamber cooling unit 3 in order to condensate water from the device chamber cooling medium on the cooling surface 35 of the device chamber cooling unit 3. In order to lower a temperature of the cooling surface 35 of the device chamber cooling unit 3, the control means 6 starts the cooling chamber fan means 52. In an alternative embodiment where a device chamber cooling unit includes an active heat exchanger, a step of lowering a cooling surface of the active heat exchanger may include starting of a pump of the active heat exchanger.

Alternatively or in addition, the dehumidification operation includes lowering a temperature of the cooling surface 15 of the internal heat exchanger unit 10 in order to condensate water from the device chamber cooling medium on the cooling surface 15 of the internal heat exchanger unit 10. In order to lower a temperature of the cooling surface 15, the control means 6 switches on the internal heat exchanger unit 10.

The receptacle 9 is configured to receive water dripping from the cooling surfaces 15 and 35. The discharge tube 92 is configured for discharging water from the receptacle 9 out of the device chamber 2. The discharge tube 92 has a capillary structure for discharging water from the receptacle 9 out of the device chamber 2.

In accordance with an alternative exemplary embodiment, water received in a receptacle is not discharged from a device chamber. Instead, the water is stored inside the device chamber in a harmless place. The stored water may be boiled in order to sterilize the water. The stored water may be used later. Storing water may be useful in a desert or other environment suffering from a shortage of water.

The cooling surface 35 of the device chamber cooling unit 3 is a smooth surface thereby facilitating a downward transfer of water along the cooling surface 35. The cooling surface 35 and the cooling surface 15 of the internal heat exchanger unit 10 each include a hydrophobic coating for facilitating dripping of water from the cooling surface to the receptacle 9. Further, the cooling surface 35 of the device chamber cooling unit 3, the cooling surface 15 of the internal heat exchanger unit 10, and an inner surface of the receptacle 9 includes anti-bacterial material.

The heating means 26 are configured for heating the device chamber 2. The heating means 26 are provided for a cold start situation in order to raise a temperature and/or lower relative humidity in the device chamber 2 to a suitable level. The heating means 26 are spaced apart from the cooling surfaces 15 and 35. In the exemplary embodiment of FIG. 1, the heating means 26 are located inside an electrical apparatus 102 accommodated in the device chamber 2. In alternative exemplary embodiments, the heating means may be located elsewhere in the device chamber 2.

The electrical apparatus 102 includes a frequency converter. In an alternative embodiment, an electrical apparatus located in the device chamber 2 may include an inverter or some other heat generating apparatus that requires cooling when operating.

The heating means 26 may be used in the dehumidification operation for heating the device chamber cooling medium in order to evaporate moisture in the device chamber 2. Transfer of the heated device chamber cooling medium containing evaporated moisture to the cooling surfaces 15 and 35 may be facilitated by the device chamber fan means 51 being configured for circulating device chamber cooling medium in the device chamber 2. In the exemplary embodiment of FIG. 1, the device chamber fan means 51 are located inside the electrical apparatus 102 accommodated in the device chamber 2. In alternative exemplary embodiments, the device chamber fan means may include one or more fans located outside the electrical apparatus. Device chamber fan means may be used for circulating device chamber cooling medium in a device chamber also in exemplary embodiments with no heating means.

The dehumidification operation may include alternately heating the device chamber 2 with the heating means 26 and lowering a temperature of the cooling surface 35 and/or cooling surface 15. The steps of heating the device chamber and lowering a temperature of the cooling surfaces may be overlapped such that the temperature lowering step begins before the heating step ends. In an alternative embodiment the heating step and the temperature lowering step are carried out simultaneously.

It will be appreciated by those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The presently disclosed embodiments are therefore considered in all respects to be illustrative and not restricted. The scope of the invention is indicated by the appended claims rather than the foregoing description and all changes that come within the meaning and range and equivalence thereof are intended to be embraced therein. 

What is claimed is:
 1. A cooling assembly comprising: a device chamber containing a device chamber cooling medium; heat exchanger means comprising at least one cooling surface in contact with the device chamber cooling medium; control means for controlling the heat exchanger means; humidity sensor means for detecting a humidity level in the device chamber; and a receptacle, wherein the control means is configured to perform a dehumidification operation as a response to the detected humidity level exceeding a predetermined threshold value in the device chamber, wherein the dehumidification operation comprises lowering a temperature of the at least one cooling surface to condensate water from the device chamber cooling medium on the at least one cooling surface, and wherein the receptacle is configured to receive water dripping from the at least one cooling surface.
 2. A cooling assembly according to claim 1, wherein the cooling assembly comprises a discharge tube for discharging water from the receptacle out of the device chamber.
 3. A cooling assembly according to claim 2, wherein the discharge tube has a capillary structure for discharging water from the receptacle out of the device chamber.
 4. A cooling assembly according to claim 1, wherein the heat exchanger means comprise a device chamber cooling unit for transferring heat out of the device chamber, the device chamber cooling unit comprising a first portion located in the device chamber and a second portion located outside the device chamber, the first portion having a cooling surface in contact with the device chamber cooling medium.
 5. A cooling assembly according to claim 4, wherein the first portion of the device chamber cooling unit is in an operating situation located lower than the second portion of the device chamber cooling unit.
 6. A cooling assembly according to claim 1, wherein the heat exchanger means comprise an internal heat exchanger unit for transferring heat from a cooling surface of the internal heat exchanger unit to elsewhere inside the device chamber.
 7. A cooling assembly according to claim 1, wherein the cooling assembly further comprises heating means for heating the device chamber, the heating means being spaced apart from the at least one cooling surface, and wherein the dehumidification operation comprises heating the device chamber cooling medium with the heating means to evaporate moisture in the device chamber.
 8. A cooling assembly according to claim 7, wherein the dehumidification operation comprises alternately heating the device chamber with the heating means and lowering a temperature of the at least one cooling surface.
 9. A cooling assembly according to claim 7, wherein the cooling assembly further comprises device chamber fan means for transferring the device chamber cooling medium from the heating means to the at least one cooling surface.
 10. A cooling assembly according to claim 1, wherein the at least one cooling surface comprises a hydrophobic coating for facilitating dripping of water from the at least one cooling surface to the receptacle.
 11. A cooling assembly according to claim 1, wherein the at least one cooling surface comprises anti-bacterial material.
 12. A cooling assembly according to claim 11, wherein an inner surface of the receptacle comprises the anti-bacterial material.
 13. A cooling assembly according to claim 1, wherein an inner surface of the receptacle comprises anti-bacterial material.
 14. A dehumidification method comprising: detecting a humidity level in a device chamber containing a device chamber cooling medium; as a response to the detected humidity level exceeding a predetermined threshold value in the device chamber, lowering a temperature of at least one cooling surface in contact with the device chamber cooling medium to condensate water from the device chamber cooling medium on the at least one cooling surface; and collecting water dripping from the at least one cooling surface in a receptacle.
 15. A dehumidification method according to claim 14, comprising: heating the device chamber cooling medium to evaporate moisture in the device chamber, the heating being carried out at a distance from the at least one cooling surface; and transferring the heated device chamber cooling medium containing evaporated moisture to the at least one cooling surface.
 16. A dehumidification method according to claim 15, wherein the heating of the device chamber cooling medium and the lowering of the temperature of the at least one cooling surface are repeated alternately. 